A Japanese nurse who tore off patients' toenails and fingernails because of a work grudge has been jailed for three years and eight months.

A court imprisoned Akemi Sato after she admitted tearing 49 nails from six female patients at a hospital in Kyoto, western Japan in 2004.

The patients were all immobile after strokes or other illnesses.

Sato, 32, acted out of anger with hospital supervisors who had criticised her, the Kyoto District Court said.

"Faced with complaints from senior workers in the workplace, she tried to let off steam while hoping the confusion in the hospital would result in her being relocated," the judge, Ryuichi Higashio, was quoted as saying by Japanese public broadcaster NHK.

Sato's defence team had called for leniency, claiming that she had been under major stress.